Ce 26569574

7/30/2019 Ce 26569574

http://slidepdf.com/reader/full/ce-26569574 1/6

Dr. Zhiyuan Chen, Maryam Temitayo, Prof. Dino Isa / International Journal of EngineeringResearch and Applications (IJERA) ISSN: 2248-9622 www.ijera.com

Vol. 2, Issue 6, November- December 2012, pp.569-574

569 | P a g e

Pipe Flaws Detection by Using the Mindstorm Robot

Dr. Zhiyuan Chen, Maryam Temitayo, Prof. Dino IsaUniversity of Nottingham, Malaysia Campus

Faculty of Science, Faculty of Science, Faculty of Engineering

AbstractThe detection of cracks in solid

infrastructure is a setback of immense

significance. Particularly, the detection of cracks

in buried pipes is a crucial step in assessing the

degree of pipe deterioration for municipal and

utility operators. The key challenge is that while

joints and laterals have an expected form, the

unpredictability and abnormality of cracks make

them hard to model. Oxidization of steel pipes inthermal insulation or padding is a severe

problem stumble upon in the petrochemical, oil

and gas industries. The most widespread ways atcurrently is time intense and labour demanding

as it entails lagging removal; check using the

usual non-destructive assessment practices such

as visual, ultrasonic or radiography; and lagging

replacement. This can also necessitate that the

tools are shutdown adding up to extra financial

burden to plant repairs and function. To examine

and continue maintaining these pipes cost somuch in terms of cash, manual labour and time,

therefore automating the process is needed.

Automation has ever since the industrial uprising

been used in industries and businesses to improve

effectiveness and competency. A greater numberof jobs are presently done by machines as an

alternative to human effort. Robotics

technologies deal with automated machines that

can take the place of humans, in hazardous or

manufacturing processes, or simply just resemble

humans. Robotics has been often seen to mimichuman behaviour, and often manage tasks in a

similar fashion. Today, robotics is a rapidly

growing field, the new research; designing and

building of new robots are to serve various

practical purposes, whether domestically,

commercially, or militarily. Many robots do jobs

that are hazardous to people such as defusing

bombs, exploring shipwrecks, and mines.

The Mindstorm robot intends to solve

the problem of detecting flaws in a pipe through

its intelligent sensors to provide a monitoring

platform along the entire distance of the pipelineand use its NXT tools to monitor and ultimately

predict the occurrence of defects. Using the

Mindstorm robot colour sensor, the Mindstorm

Lego robot can detect the leakages in a pipe as

dark colour modelled with a black tape and can

also detect the cracks modelled with a white tape

there by reducing the shut down time of the

process.

Keywords: Mindstorm Lego, NXT, Pipeline

Leakage, Automation, Robot C, NXT-G,

Robotics, sensor.

1IntroductionTransportation of fluid from the point of

production to different points for easy access for end

users has been a necessity and hence the importanceof construction of pipelines. Most of these pipelinestransport toxic products though very essential for

day-to-day activities such as in the oil and gas

industry, therefore direct exposure of the pipe to theenvironment is dangerous and hazardous [S. K.

Sinha and F. Karray][7]. Buried pipeline areconstructed to protect the pipes from environmentaland atmospheric influence such as impact, abrasion

and corrosion that can lead to pipe destruction. Thedifferent types of flaws in a pipe include: corrosionand wear (which can be as a result of change in

atmospheric condition), cracks, dent and holeleakages. These flaws could be as a result of weather changes, long use of the pipe (most pipes

are designed to last for 25years irrespective of whatflows inside them), intentional and unintentional

third party damage such as accident, sabotage, terrorand theft. [Timur Chis and Andrei Saguna][8].Most pipelines operate for many years without muchattention to mechanical changes in the pipe. Some of these pipes are left partially full for some period and

this can lead to corrosion as some of these productsthat are being transported are corrosive in nature.The design and construction of the pipeline couldlead to leakages at some poor construction joints.Likewise, the operation design guidelines need to be

studied. There are times where the pipes aredesigned for a certain maximum temperature andpressure and usage under a higher degree can lead to

the pipeline failure. [Timur Chis and AndreiSaguna][8].

Intentional damage unfortunately seems to

be on the high side than the unintentional oraccidental damage. This is more common withpipelines transporting high-value products and isusually highly flammable and this has led to loss of lives and properties in so many regions. A recentpipeline vandalisation that happened in Nigeria ledto over loss of 100 lives as the pipeline was carrying

fuel from a state-owned refinery in the city of PortHarcourt to the city of Enugu which is 140miles

away in north direction. [Daily mail news][3]Therefore, the oil and gas industries and

other fluid transport based industries tend to pay

7/30/2019 Ce 26569574




570 | P a g e

attention to leakage detection as failure to detect canlead to loss of life and property, direct cost of loss of products and lie-down time leading to directfinancial loss to the industry, environmental

pollution and this will necessitate the need forenvironmental clean-up thereby incurring more

production/management cost. In a more criticalcase, it can lead to possible fines and legal suitscosting the company many millions of dollars.

[Timur Chis and Andrei Saguna][8].The detection of flaws that could lead to

leakages in buried concrete pipes has been an area

of great concern to the oil and gas industry andwater resource based industry. The recognition of flaws in underlying channel is an important measurein examining the extent of tube impairment for

public and service workers. The major problem isthe difficulty in modelling detection of cracks as aresult of it irregularity and randomness unlike pipe

joints and dents that can be easily detected throughit predictable appearance [S. K. Sinha and P. W.

Fieguth][6]. Figure 1 shows the presence of a crack on a wall.

Figure 1: Presence of crack on a wall. (This showsthe presence of crack in a wall as it appearance varyfrom one wall to another)

The corrosion of steel pipes as a result of rapid change in weather condition, thermal

insulation, pressure and erosion is a major crisis inthe petrochemical, oil and gas industries. The mostcommon ways at present is time consuming and

labour intensive as it involves insulation removal;assessment using the usual non-destructiveassessment practices such as visual, ultrasonic or

radiography; and insulation replacement. This canalso require that the equipment is shutdown addingadditional economic burden to plant maintenance

and operation. To monitor and maintain thesepipelines cost efficiently and effectively in terms of

money, labour and time, automating the process isneeded [R. J. Barnes][5].

Automation has from the time of the industrialuprising been used in industries to enhancecapability. A growing number of jobs are at presentcarried out by machineries as a replacement for

human effort. The Science of Robotics deals withmachines that can be automated in order to take the

place of humans, in risky or sensitive environment,or simply perform actions that resemble humancapability. Robotics has been designed often time to

act like human by mimicking human behaviour, andoften has been able to manage tasks in an expectedway as human behave. Recently, robotics has been

growing rapidly; the new research; designing andbuilding of new robots are to meet differentpractical purposes, which include domestically,commercially, or militarily. Today’s robots perform

jobs that can result to loss of lives or could causesevere damage to people. Such activities includedeactivating bombs, exploring a shipwreck, and

mines.

Robotics has become an effective toolwithin the scope of education in the past few years[Amini F, Vahdani R][1]. It has successfullyincorporated features such as simplified

programming skill, and easy way of building robotat a low/middle cost showing interrelationshipbetween courses. This has been the keystone for the

achievement of robotic application in education[Amini F, Vahdani R][1]. Lately, a movementwhich considers robotics as an instrument to shedmore light to other components in the curriculum

rather than the subject itself may be observed, andparticularly in the field of computing and electronics[J. A. G. Ilder, M. I. P. Eterson, and J. A. W.Right][4]. The major advantage has been thepractical way of impacting knowledge to students in

the course of learn, leading to a betterunderstanding of ideas, and the interdisciplinaryorder of the work that is to be done. [2][B. Shih, C.

Shih, C. Li, T. Chen, Y. Chen, and C. Chen]

Mindstorm lego is a robotic tool set fromLEGO that is primarily made for children as a gameset. A major component of the Mindstorm set is the

NXT which contains the main processor that cancontrol four input sensors with three outputs sensorsconnected to the NXT externally. The brick can beconnected to other different peripherals such as the

speakers as effectors, the light, infrared, ultrasound,interactive servomotors and touch sensor. The LegoNXT Software Development module had

successfully used challenges and emulations toimprove the student experience, but these challengeswere somewhat artificial in nature. [2][B. Shih, C.

Shih, C. Li, T. Chen, Y. Chen, and C. Chen]

The Mindstorm robot intends to solve this

problem through its intelligent sensors to provide ascreening stage along the complete length of the

7/30/2019 Ce 26569574




571 | P a g e

pipeline and use its NXT tools to examine andeventually calculate the expected happening of defects.

2 MethodologyTo carry out this research, we have used

the model robot NXT 2.0 from Lego Mindstorm, theNXT. Program development has been done, a smallRobotC-based firmware system that runs on the

NXT brick. The Mindstorm software buildingblocks were also used for this project.

The practice is to get the robot, aided by

their functions and motion sensors, get movedthrough a pipe and detect crack which is modelledwith a black tape for a hole and a white tape for the

crack on harsh coloured background of the pipe.This was presumed since a hole would leave thepoint blank and therefore dark while a crack would

only cause a little deviation from the original colour

of the pipe. In addition, the robot will have to stop if it detects the crack for few seconds and calculate the

distance covered by to the get to the point of crack and display the number of cracks detected and if nocrack detected, display “no crack”.

2.1 HARDWARE DESIGN The design was made following the

procedure read in the enclosed instructions on thebox of parts of the robot.

Modification was then made to the

hardware as shown in fig 6 to use the colour sensor.The Mindstorm colour sensor has the ability of

performing three functions at a time, colourrecognition (which enable it recognises the differentcolours in the pipe, it is capable of recognising 6different colours), Measuring light intensity of itenvironment (with this, it is able to handle light

reflection in it surrounding) and it can also be usedas colour lamp.

The design incorporates:

Three servo motors that drive the robot.

The motors are connected to port A, B, C,.These motors are responsible for themovement of the robot.

The NXT which is the brain of the robot.The program is downloaded to the NXTusing the Bluetooth or USB port. The NXT

display is used to display informationrunning on the program.

The colour sensor to detect the cracks andholes in the pipe.

Six AA batteries to power the robot.

Other things in the design are theconnectors that connect the different

functional components together.

Figure 2: The Mindstorm robot with the

coloured sensor attached to it to detect the flaws

The robot is programmed to give a beepsound and to wait for two seconds once a flaw isdetected and to increase its counter by 1.The NXT brick which manages and controls theother components, and offers a small screen

interface and 4 buttons the brick also emits sounds.(Figure 7)

Figure 3: The NXT brick

2.2 Development of flaw detection in RobotCRobot C has a commercialised program for

the Mindstorm thereby giving it an idealprogramming environment for Lego Mindstorm.ROBOTC runs a much standardized firmware that

permits the NXT to download and run programs in afast speed, and also compact the files so as to fix a

7/30/2019 Ce 26569574




572 | P a g e

huge number of programs inside the NXT. Just likeany other languages running on NXT, ROBOTCneed the firmware to be downloaded from theROBOTC robot tool in-order to run.

For the implementation of the code has opted for ascheme of priorities within a finite loop, which

evaluates the three conditions for which the robotshould act.

First it checks if the colour of the surface of

the object read by the coloured sensor is black (indicating a hole) as defined in the program. If so,then the robot stops for 5 seconds while the warning

sound plays which act as an alarm. It increases itcounter by 1 and the total number of cracks detectedis displayed by the last detection. The distancecovered is also calculated using the motor function

and this is also displayed on the NXT display. Thischeck will be carried out within a specified time inthe code, to avoid excessive use of the processor in

the sensor readings and an infinite loop.Secondly, it checks for a crack which is

modelled with a white tiny colour of 0.2cm widewith the help of it colour sensor. If the white colouris detected, the robot pauses for 2 seconds (not aslong as a hole as this is a minor case compared to

the hole) and makes a warning sound as an alert. Italso increases a separate counter for this andcalculates the distance covered and this information

is displayed on the NXT display as indicated in theprogram.

Finally, it runs the code for the case wherethe robot is not detecting any hole or crack

(modelled as the black and white colour). In thiscase, the robots just move straight as no obstructionis detected. It then displays a “no crack” message to

indicate that no crack is detected. However, a timelimit has been set to avoid over used of the

processors.The Robot C screen shot is as shown below inFigure 4:

Figure 4: RobotC snapshot

2.3 NXT-GNXT-G v2.0 is a user friendly graphical

interface programming environment that is comeswith the NXT kit. With a good assembly of blocks

and data wires to sum up complexity, NXT-G iscapable of being applied in a real world

programming challenge. Similar "sequence beams"are in reality matching threads, therefore thissoftware is pretty fine for running a good number of

similar sense/respond loops (For instance: wait 30seconds, play a "beep" sound at high volume if battery level is good, iterate), or merging

independent management using the Bluetooth or anyother "remote control". The programming languagepermits virtual tools for all LEGO labelled and agood number of 3rd party sensors/components. The

Version 2.0 (which is the version being used for thisproject) has new tutorial problems, a remote control,custom images and sound making, and latest Lego

colour sensor support.The graphical program was built by

making the robot wait for one second before startingto move. Then the light sensor was applied to detectthe range of colour that indicates a hole. If thecolour is black which indicate the presence of a

hole, it executes the first layer of the program asshown in figure 8 below. If otherwise, it moves tothe next layer, where it also tests to see if the colour

present is white. If a white colour is detected, then itfollows the program on the upper layer of thesecond phase of the program and if otherwise, thelast layer will be run on the robot.

However, in each of these layers, a set of blocks areused to program the activity of the robot and thewires are used to connect one related block to theother.

The first layer, after detecting the hole

increases its counter by 1 and this information isconverted into the text format and stored in the NXTmemory. The text is then displayed on the NXT

display and the robot continues its journey. Thedistance travelled on detection is calculated anddisplayed.

A similar thing is repeated on the upperlayer of the second layer. It also increases its

counter by one, converts it into text and display thenumber of cracks detected modelled with the whitecoloured tape, and then moves on. The distancetravelled is also calculated and displayed.

The lower layer of the program detects no othercolour that means no crack has been detected andtherefore displays “no crack” on the NXT display

screen.The software building block is as shown below:

7/30/2019 Ce 26569574




573 | P a g e

Figure 5: NXT G Snapshot

3 ResultThe robot “kazo” was able to move using

the three servo motors attached to it. Using themove block in the program enables kazo to move ina straight line. Each of these motors has a built-inrotation sensor which controls the robot movement

and was used to calculate the distance covered bythe robot. One rotation of the robot is equal to 360degrees with an error space of +/- one degree. The

outcomes of this experiment are shown in Table 1-9with the summary of the result on table10. Theexperimental data underlying the transition in time

preset in this model were collected during the courseof the experiment of the different types of flaws at

different length. Each box in table 1-9 shows a yesor no with a value of yes if the robot was able tocarry out the specified action at the point of monitoring of the pipe and a no if the action was not

carried out at the particular speed.

The overall trend in these results agreeswith our qualitative expectations in our aims andobjective to automate the detection of flaws thereby

reducing the shut down time. The speed rate of 20%takes longest period but demonstrates the greatestreliability, whereas a speed rate of 60% is best interms of speed with a much lower success rate in

detection. Speed 40 tries to balance the two with anaverage speed and a good reliability. Keeping thespeed at 30% is recommended from the result as this

gives a better reliability by detecting all cracksexcept the thread-like crack which causes little or noharm to the pipe and at the same time reducing theshut down time of the system.The distance covered at each point of the flaw wascalculated and displayed through the servo motors

sensor by taking account of the rotation in motor Ain 360

0thus:

Circumference = 2πr

The diameter was measured to be 3.5cm. Therefore,

the radius is 1.75cm.Distance travelled = 2πr X number of rotations= 3.5π X number of rotations

=11 X number of rotationsThe above result can be summarised in the tablebelow:

Table 1: Summary of the result

Flaws/Speed 20 30 40 50 60

3cm hole Yes Yes Yes Yes Yes2cm hole Yes Yes Yes Yes Yes

1cm hole Yes Yes Yes Yes Yes

0.5cm hole Yes Yes Yes Yes Yes

0.1cm hole Yes Yes Yes Yes No

0.1cm crack Yes Yes Yes No No

0.05 crack Yes Yes No No No

Thread-like

crack

Yes No No No No

Figure 6: Chart for the result

Number of detected flaws

Time

Figure 7: Graph showing the rate of detection as

time changes

In general, it was found that the assumptionregarding the Mindstorm’s performance in detecting

the flaws of the pipe varies as the speed increases. A

10% change in speed increases the reliability of detection as shown in the gradient of the graph in

7/30/2019 Ce 26569574




574 | P a g e

figure 27. While the simplicity of this project’s

model forces us to accept certain inaccuracies,particularly in the modelling of the flaws, it allowsus to perform meaningful analysis on the rate of

detection in the Mindstorm robot.From the above analysis of the experiment, the

following can be deduced: The bigger holes can be detected even at a

very high speed of the robot.

Kazo is capable of detecting cracks that aremore obvious to the eye.

The higher kazo moves the less likely it

detects minor cracks.

The distance was calculated and this canaid the repair process.

4 ConclusionThis project was able to build and program a

Mindstorm Lego robot to detect holes and cracks in

a pipe using the colour sensor of the mindstormrobot. This write up shed light on the basic

components of the lego from building the robotfrom the pieces of bricks to the building blocks of the NXT2.0 software for programming the robot.

The program run on the robot was explained and therobot was able to detect the major flaws in the pipein real time.

4.1 FURTHER RESEARCHThis work has been able to successfully

detect flaws in the pipe. Nonetheless, there are stillareas that were not covered as a result of timelimitation and other factors. Further areas of

research include:

The use of a stronger ultrasonic sensor todetect the cracks and holes. This was not

covered as it amounts to hacking the LegoMindstorm and might lead to withdrawal of the guarantee in the kit. However, this need

to be tried as it is hope to be more practicaland can come out with a better result bydetecting the cracks once it is visible to the

eye.

Application of machine learning fordetection. This is still an active research

area, as we need to know if the MindstormLego can learn the original condition of thepipe. This also seems to be a betterapproach as some of these pipes are foundwith minor and ignorable faults initiallyand the robot should not detect them as a

major fault.

The work of K. Sinha and P. W. Fieguthstill need to be looked into using the

concept of image processing to take thedifference between two images.

All the afore-mentioned are only detecting

the flaws and remain uncompleted if therepair methodology is not yet automated toreduce the downtime of the pipeline.

Though, we have been able to calculate thedistance travelled before detection so as tomake it easy in the course of repair tolocate the flaw.

References

[1] Amini F, Vahdani R (2008). Fuzzy optimalcontrol of uncertain dynamic characteristicsin tall buildings subjected to seismic

excitation. J. Vibration Control 14: 1843 –

1867.[2] B. Shih, C. Shih, C. Li, T. Chen, Y. Chen,

and C. Chen, “Elementary school student ’s acceptance of Lego NXT : The

technology acceptance model , a preliminary investigation,” vol. 6, no. 22,

pp. 5054 – 5063, 2011.[3] http://www.dailymail.co.uk/news/article-

185648/105-dead-Nigeria-fuel-pipe-

blast.html[4] J. A. G. Ilder, M. I. P. Eterson, and J. A.

W. Right, “A VERSATILE TOOL FOR STUDENT PROJECTS : AN ASM

PROGRAMMING LANGUAGE FORTHE LEGO MINDSTORM,” vol. 3, no. 1,

pp. 1 – 14, 2003.[5] R. J. Barnes, “Underlying the performance

of pipeline leak-detection systems,” no.December, pp. 44 – 51, 1999.

[6] S. K. Sinha and P. W. Fieguth, “Automated

detection of cracks in buried concrete pipeimages,” Automation in Construction, vol.

15, no. 1, pp. 58 – 72, Jan. 2006.[7] S. K. Sinha and F. Karray, “Classification

of underground pipe scanned images usingfeature extraction and neuro-fuzzyalgorithm.,” IEEE transactions on neural

networks / a publication of the IEEE

Neural Networks Council, vol. 13, no. 2,pp. 393 – 401, Jan. 2002.

[8] Timur Chis and Andrei Saguna, “PipelineLeak Detection Techniques”, Annals.

Computer Science Series, 5th

Tome 1st

fasc.-2007

http://www.dailymail.co.uk/news/article-185648/105-dead-Nigeria-fuel-pipe-blast.html






Documents

Ce 26569574